Relationship between microstructure and mechanical properties of a 5% Cr tempered martensitic tool steel

N Mebarki (1) , Denis Delagnes (1) , Pascal Lamesle (1) , François Delmas (2) , Christophe Levaillant (1)

1 CROMeP - Centre de Recherche Outillages, Matériaux et Procédés
2 CEMES - Centre d'élaboration de matériaux et d'études structurales

Relevant microstructural characteristics ensuring a good mechanical strengthening up to 600degreesC of a tempered martensitic steel containing 5 % Cr (AISI H11) were investigated using transmission electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction and extraction of carbides. Softening induced by tempering and cyclic loading is related to a strong reduction of the dislocation density estimated by X-ray peak profile analysis (modified Williamson Hall and modified Warren Averbach analysis). Moreover, the coalescence of chromium and vanadium carbides is involved in the yield strength decrease above 600degreesC and during cyclic loading.

Mots clés: Second tempering; Carbides; Fatigue; Martensitic steel

Domaines: Mécanique des matériaux [physics.class-ph]

N Mebarki, Denis Delagnes, Pascal Lamesle, François Delmas, Christophe Levaillant. Relationship between microstructure and mechanical properties of a 5% Cr tempered martensitic tool steel. Materials Science and Engineering: A, 2004, 387-389, pp.171-175. ⟨10.1016/j.msea.2004.02.073⟩. ⟨hal-01715085⟩